Tube forming die



June 15, 1948. A. N. DE WlLDE ETAL TUBE FORMING DIE Filed July 14, 1944 Patented June 15, 1948 UNITED STATES PATENT OFFICE 2,443,416 TUBE FORMING ma Albert N. De Wilde and William W. Mansfield,- Goshen, Ind., assignors to Penn Electric Switch 00., Goshen, Ind., a corporation of Iowa Application July 14, 1944, Serial No. 544,984

2 Claims. 80-42) Our present invention relates to a die for forming tubes by either restricting the open end thereof or closing it.

One object of the invention is to provide a forming die which may be mounted in a machine for rotation and has a socket into which the tube such as a copper tube may be inserted and forcibly fed into the die, the die during rotation progressively contracting the end of the tube and closing it if desired.

Another object is to provide a die capable of closing a tube end, the die being of simple and inexpensive construction and designed to operate eiiectively in its intended capacity.

Still another object is to provide a die having therein a roller for contacting the end of the tube inserted into the die and effecting a heating of the tube end to aid in the contraction thereof.

A further object isto provide a die from which the roller can be readily removed and replaced after it is worn away.

With these and other objects in view, our invention consists in the construction, arrangement and combination of the various parts of our device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in our claims, and illustrated in the attached drawings, in which:

Figure 1 is a partial sectional view through a die embodying our invention and showing a tube being formed therein.

Figure 2 is a side elevation of the roller 0! the die. 1

Figure 3 is a sectional view of the body of the die from which the roller with its retainer plug has been removed.

Figure 4 is a side elevation of a retainer plug for the roller.

Figure 5 is a sectional view similar to a portion of Figure 1 showing the tube completely closed.

Figure 6 is a sectional view of an end of the partially closed tube showing a capillary tube soldered thereto.

Figure 7 is a sectional view on the line 1-1 of Figure 1 to show the coaction of the roller and a seat in the die with the tube during the forming operation.

On the accompanying drawing, we have used the reference numeral It to indicate the body of the die formed of suitable steel or the like and of any suitable length for holding in a machine, whereby the die is rotated. The die, for instance, may be chuckedin a lathe or the body "I may constitute a shaft suitably mounted in bearings and driven by an electric motor or the like. The

speed of rotation may vary considerably and we have found speeds of 500 to 1000 R. P. M. suitable for the size of tubing 12 illustrated in the drawing. Of course, larger and smaller sizes of dies may be made for other sizes of tubing, and the speed of rotation of the die may be varied to obtain best results. The tube [2 may be held against rotation by a clamp or the like I3.

The body l0 has a bore l4 formed therein for the purpose of forming a seat for substantially one-half of the tube as will hereinafter appear. Into the side of the body ID, a socket I6 is cut and the upper portion thereof is threaded as indicated at H. A hole l8 extends downwardly from the center of the socket I8 as viewed in Figure 3 to receive a pin.

The pin is illustrated at l9 and rotatably mounted on it is a roller R. The roller R has a disc-like portion 20 and a concavely shaped cone portion 2|. A spacing shoulder is provided at 22. The roller R is joumaled on the pin l9 and the outer end of the pin is mounted in a socket 23 of a retainer plug 24. The plug 24 may be positioned and removed by a suitable spanner wrench.

Practical operation In the operation of our tube forming die, assuming the body ill to be rotating at the proper speed, the tube 12 may be inserted into the bore l4 and forced against the concaved portion 2| of the roller R. Manual force can be used against the clamp l3 or a screw or hydraulic means may be provided for advancing the clamp while holding it against rotation. As the body [0 rotates, the roller R. will be rotated by its friction against the stationary tube l 2.

Due to the concavity 2| and the heat generated by the friction between the tube and the roller and also between the lower half of the bore l4 and the tube, the tube will start deforming on its inner end as shown in Figure 1. The deformation may be continued until the tube is entirely closed, as in Figure 5, and we have found that such closing of the tube results in a gas and liquid tight closed end on the tube, so that our die is suitable for forming capillary bulbs from short lengths of tubing.

The other end of the tube may then be partially closed as in Figure 6, leaving only enough opening to receive a capillary tube 25 of the desired size. The capillary tube may be inserted into the bulb and soldered as at 26 in the usual manner. .To insure against any possible leakage at the closed end of the bulb, it may also be solcontact, there are spaces indicated at I! in Figure 1, which serve as relief points into which the tube end my deform during the forming operation. We have found that this arrangement permits the roller R to partially or fully close the end of the tube with a maximum of eiiiciency and accuracy.

Some changes may be made in the construction and arrangement of the parts of our device without departing from the real spirit and purpose of our invention, and it is our intention to cover by our claims, any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope without sacrificing any of the advantages thereof.

We claim as our invention:

1. In a tube forming die of the character disclosed, a rotatable body having a bore therein adapted to receive the end of a tube to be formed, said body having a lateral socket intersecting said bore, a roller in said socket for contacting the tube end and for being rotated by contact therewith as said die is rotated and said tube is held against rotation, a plug'in said socket outside said roller, a pin on which said roller rotates, said pin being carried by said plug and the portion of said body at the bottom of said socket, said roller 2. In a tube forming die of the character dis- I closed, a rotatable body having a bore therein adapted to receive the end of a tube to be formed. a socket in the side of said body and intersecting said bore to a depth which terminates at substantially the axis of rotation of said body, a roller in said socket dor contacting the tube end, said roller having a concaved cone-shaped portion to progressively bend the inner end of the tube toward a. closed position while the tube is forced into said bore. means for retaining said roller in said socket comprising a plug threaded into the outer portion of said socket.

ALBERT N. DE WILDE. WILLIAM W. MAN.

REFMENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,030,818 Harter Feb. 11, 1936 2,313,474 Hill Mar. 9, 1943 FOREIGN PATENTS Number Country Date 546,933 France Sept. 6, 1922 577,311 nce -.....t June 8, 1924 

